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On today’s SMF Ad Hoc conference call, during presentation of “Optical Specifications of SMF PMDs Study” it was suggested that the only time there is peaking in a PAM-4 waveform is when using the “Nyquist PAM-4” approach. Peaking is a function of TX bandwidth and pulse shaping. If TX is driven by a DAC, then pulse shaping is limited by the DAC sampling rate and analog bandwidth. In the case of the 100G/wavelength proposals in .bs, even for “Broadband PAM-4”, the DAC imposes a severe limitation on pulse shaping, and in all cases there is non-negligible peaking. A clear example of peaking can be seen in “Single Wavelength over 112Gb/s PAM4 …” by Way and Chan, despite the obvious design preference to have none. http://www.ieee802.org/3/bs/public/14_09/way_3bs_01a_0914.pdf#page=6 (see 3rd and 4th images) This peaking is unavoidable because of the DAC and Driver limitations listed on the following pages. A complete link budget has to account for reduction in TX OMA to manage the clipping level due to component limitations. It is not acceptable to ignore this penalty. Chris From: Anslow, Peter [mailto:panslow@xxxxxxxxx] Hi, As previously announced, there is an SMF Ad Hoc meeting starting at 7:30 am Pacific Today, Tuesday 30 September. I have currently received two requests for presentations so the draft agenda is: Attendees names and affiliations will be taken from the Webex participants list. If you attend via phone only, or if your employer and affiliation are different, please send me an e-mail. Discussion · IEEE patent policy reminder o http://www.ieee802.org/3/patent.html · Approval of the agenda · Approval of the draft minutes from 19 August 2014 call · Presentations o Updated Considerations on 400Gb/s Ethernet SMF PMDs Peter Stassar, Huawei o Optical Specifications of SMF PMDs Study Chris Cole, Finisar Discussion Peter Anslow from Ciena has invited you to join a meeting on the Web, using WebEx. Please join the meeting 5-10 minutes early so we may begin on time. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Topic: "P802.3bs SMF Ad Hoc" Date & Time: Tuesday, 30 September 2014 at 15:30, GMT Summer Time (London, GMT+01:00) To join web meeting click here: https://ciena.webex.com/ciena/j.php?MTID=m6572f354a7a856a704aec5ef0fb5e0e2 Meeting password: IEEE (please note passwords are case sensitive) Teleconference: Provide your phone number when you join the meeting to receive a call back. Alternatively, you can call: 4438636577 (United States) 2064450056 (Canada) 4006920013 (China) Show global numbers: https://www.tcconline.com/offSite/OffSiteController.jpf?cc=2070125535 Conference Code: 207 012 5535 Meeting number: 689 183 943 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Additional Notes: - To add this meeting to your calendar program click the following link, or copy the link and paste it into your Web browser: https://ciena.webex.com/ciena/j.php?MTID=m18ec485fd6625cb9308800f19f10c384 - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - Pete Anslow | Senior Standards Advisor |